Class D amplifier

Abstract

The invention refers to an amplifier ( 1 ) comprising a switchable capacitive divider ( 10 ) for dividing a supply voltage delivered to the amplifier ( 1 ), the switchable capacitive divider being coupled to a coupling circuit ( 15 ) via a first wire and a second wire, the coupling circuit determining a connection path between said first and second wire and a first capacitor (C 2 ) and a switchable power circuit ( 20 ).

1. An amplifier comprising:
 a switchable capacitive divider for dividing a supply voltage delivered to the amplifier, the switchable capacitive divider including 
 a first switch coupled to a second switch via a second capacitor, 
 the first switch being further coupled to a first terminal of a third switch, 
 the second switch being further coupled to a first terminal of a fourth switch, 
 a second terminal of the third switch being coupled to a second terminal of the fourth switch, the second terminal of the third switch also coupled to an output node; 
 a coupling circuit, coupled to the switchable capacitive divider by a first wire, for determining a connection path between said first wire, a first capacitor and a first switchable power circuit, 
 the first capacitor being coupled to the output node, said output node being further coupled to the first switchable power circuit via a fifth switch having a first terminal coupled to the output node and a second terminal coupled to a first power terminal. 
 
     
     
       2. An amplifier comprising:
 a switchable capacitive divider for dividing a supply voltage delivered to the amplifier, the switchable capacitive divider including 
 a first switch coupled to a second switch via a second capacitor, 
 the first switch being further coupled to a first terminal of a third switch, 
 the second switch being further coupled to a first terminal of a fourth switch, 
 a second terminal of the third switch being coupled to a second terminal of the fourth switch, the second terminal of the third switch also coupled to an output node, the output node being coupled to a first power terminal and a fifth switch being coupled between the first capacitor and the output node; and 
 a coupling circuit, coupled to the switchable capacitive divider by a first wire, for determining a connection path between said first wire, a first capacitor and a first switchable power circuit. 
 
     
     
       3. The amplifier according to  claim 2 , wherein the first switchable power circuit comprises a sixth switch and a seventh switch, a first terminal of the sixth switch being coupled to a first terminal of the seventh switch, the sixth switch also coupled to the first power terminal. 
     
     
       4. The amplifier according to  claim 3 , wherein the amplifier is a bridge amplifier having the first power terminal coupled to an output load. 
     
     
       5. The amplifier according to  claim 4 , further comprising a second switchable power circuit, the amplifier coupled to a first terminal of a load, the second switchable power circuit having its output power terminal coupled to a second terminal of the load, and an eighth switch for coupling an output of the switchable capacitive divider to a second power terminal. 
     
     
       6. An amplifier comprising:
 a switchable capacitive divider for dividing a supply voltage delivered to the amplifier, 
 a coupling circuit, coupled to the switchable capacitive divider by a first wire, for determining a connection path between said first wire, a first capacitor and a first switchable power circuit, wherein the amplifier is internal to an integrated circuit, the integrated circuit including a voltage multiplier coupled to the supply voltage that supplies the amplifier with a variable voltage. 
 
     
     
       7. An amplifier comprising:
 a switchable capacitive divider configured to divide a supply voltage delivered to the amplifier, the switchable capacitive divider including: 
 a first switch, a first capacitor, and a second switch coupled in series, the capacitor separating the first and second switches, a connection between a first end of the capacitor and the first switch forming a first reference node, and a connection between a second end of the capacitor and the second switch forming a second reference node; 
 a third switch having a first end coupled to the first reference node and a second end coupled to an output of the switchable capacitive divider circuit; and 
 a fourth switch having a first end coupled to the second reference node and a second end coupled to the output of the capacitive divider circuit; and 
 a coupling circuit for determining a connection path between the output of the switchable capacitive divider, a second capacitor, and a first switchable power circuit, the coupling circuit including one or more switches and having a first terminal coupled to the output of the switchable capacitive divider circuit, a second terminal coupled to a second capacitor, and a third terminal coupled to a switchable power circuit. 
 
     
     
       8. The amplifier of  claim 7 , wherein the coupling circuit includes:
 a fifth switch having a first end coupled to the output of the switchable capacitive divider circuit and a second end coupled to the switchable power circuit; and 
 a sixth switch having a first end coupled to the output of the switchable capacitive divider circuit and a second end coupled to an additional switchable power circuit.